Pencil sharpener



1, 1938. a L ULLMAN 2,106,963

PENCIL SHARPENER Filed June 12, 1935 Patented Feb. 1, 1938 UNITED STATES PATENT OFFICE PENCIL SHARPENER Morris L. Ullman, Milton, Mass.

Application June 12,

1 Claim.

This invention relates generally to pencil sharpening devices, and particularly to devices of the character wherein provision is made for effecting the retention, in and by such devices, of the wood shavings and the finely divided graphite pared from pencils in the use thereof.

The primary object of my invention is to provide a pencil sharpener in the use of which the wood shavings pared from pencils are compacted, and, by virtue of becomingcornpacted, are effectively retained by the pencil sharpener during the pencil sharpening operation. The secondary object of my invention is to provide such a pencil sharpener from which such compacted masses of wood shavings, together with the accumulations of finely divided graphite, can be discharged in a very simple manner. These and other objects of my invention, which will readily occur to those skilled in the art, are realized in the device illustrated in the accompanying drawing wherein:

Fig. 1 is a side elevation, partly in detail, of the pencil sharpener.

Fig. 2 is a sectional view of the pencil sharpener in use, the section being taken along the line 2, 2 of Fig. 4, showing the manner of accumulation of the wood shavings and of the finely divided graphite during the pencil sharpening,

operation.

Fig. 3 is a plan view, partly in detail, of the pencil sharpener, showing the arrangement of the paring blade in relation to the body of the pencil sharpener, and to the pencil receiving chamber thereof: the lateral cavities in the body of the pencil sharpener for the reception of the pivots of the cover are also shown.

Fig. 4 is a rear elevation, partly in detail, of the pencil sharpener, showing the relationship of the edge of the paring blade to the longitudinally vertical plane of symmetry of the chamber for the reception of the wood shavings and finely divided graphite pared from pencils during the pencil sharpening operation, and showing also the mode of pivoting the cover upon the body of the pencil sharpener.

Fig. 5 is a front elevation of the pencil sharpener.

Fig. 6 is a plan view of the pencil sharpener.

Fig, 7 is a side elevation of the pencil sharpener with the cover rotated to permit the discharge of a compacted mass of wood shavings and an accumulation of finely divided graphite.

As shown by these illustrations, the present invention comprises broadly a pencil sharpener, provided with a cover pivoted thereupon, and

1935, Serial No. 26,203

fitting snugly to the front and sides thereof, and of a conformation adapted to accomplish purposes hereinafter to be set forth: the specific embodiment of the present invention may be particularly described as follows:

The body l of the pencil sharpener, composed of any suitable material such as synthetic resins, is provided with a longitudinally disposed chamber forthe reception of the ends of pencils to be sharpened. This chamber consists of the sequence of the U shapedcylindrical space 2, the truncated conical space 3, and the truncated cylindrical space i, extending throughout the entire length of the body I. A rectangular slot 5 in the top of the body I communicates with this chamber. Inset into the top of the body 5, with its edge overlapping one edge of the slot '5, and held fixed in position by the screw '3, is the paring blade 6 whose edge projects slightly into the U shaped cylindrical space 2 and the truncated conical space 3. The cover 8, composed of sheet metal in the shape shown, having turned down flanges for sides and front and a top struck up into a conico-cylindrical surface, is

pivoted upon the body I near its rear end by 2 means of the pivots 9 rotating in cavities of the body The cover, when in position, fits snugly to the front and sides of the body l, thus providing a chamber for the reception of the wood shavings and finely divided graphite pared from pencils during the pencil sharpening operation, and forestalling the escape of any wood shavings or finely divided graphite by way of the front end or the sides of the pencil sharpener. Particular attention is called to the fact that when the cover 8 is in position, the rear end Ill of the conical surface of the cover is positioned considerably forward of the rear end of the edge of the paring blade 6.

A device of the character described, occupying a volume of approximately one cubic inch, and therefore readily portable, may be manufactured cheaply and sold at a popular price: despite its great simplicity, it is highly satisfactory and effective for all purposes for which it is intended; and its use is attended with cleanliness to a degree attainable only in a costly non-portable device.

In the use of this pencil sharpener, the novel advantages of my invention are readily perceived. As the pencil is rotated in a clockwise manner in the pencil sharpener, wood shavings and finely divided graphite accumulate in the manner shown in Fig. 2 at l2 and [3, respectively. The rate of accumulation of wood shavings at any point along the edge of the paring blade 6 is proportional to the diameter of the conical chamber 4 at that particular point, so that the rate of accumulation of wood shavings at the rear extremity II of the paring blade 6 will always be greater than the rate of accumulation of wood shavings at points forward of the point I I. In actual practice, I have found that, in the sharpening of a pencil, the amount of wood shavings accumulating in the region forward of the point 10 will just fill the space provided, but the amount of wood shavings accumulating in the region back of the point III will become packed tightly in the space provided, as is shown at I2 in Fig. 2. In consequence, the wood shavings so compacted form a plug which is firmly retained in position, thus preventing the escape of any wood shavings or finely divided graphite by way of the rear end of the pencil sharpener, even when the pencil sharpener is held vertically. The wood shavings so compacted can be dislodged from the chamber by way of the rear end only with difllculty, but the pencil sharpener can, of course, be emptied very readily by rotating the cover 8 upon its pivots 9 and allowing the compacted wood shavings and the finely divided graphite to fall from the pencil sharpener. That this compacting efiect actually occurs became apparent to me in the course of experiments made upon such a pencil sharpener, the cover of which was pivoted near the front end of the body I: in these experiments, the accumulating wood shavings invariably displaced the cover from the body in a rotational manner. Thus I was lead to realize that were the cover pivoted near the rear end of the body I, the compacting of the wood shavings would cause them to be retained within the chamber. In subsequent experiments made upon pencil Sharpeners, the covers of which were pivoted near the rear ends of their bodies, I found that superior compacting efiects could be realized in a clockwise operable pencil sharpener when the edge of the paring blade is positioned, as shown, to the left of the longitudinally vertical plane of symmetry of the chamber for the reception of the wood shavings and finely divided graphite: in a pencil sharpener so constructed, the compacting of the wood shavings proceeded uniformly throughout the width of the chamber. Such uniform compacting efieot can, of course, be realized in any construction wherein such relationship of the edge of the paring blade 6 to the longitudinally vertical plane of symmetry of the chamber is preserved: thus, for example, if the edge of the paring blade 6 is positioned at the mid point of the width of the body I, shifting of the conico-cylindrical surface of the cover is required to reestablish the proper relationship between the edge of the paring blade 6 and the chamber for the reception of the wood shavings and finely divided graphite.

The compacting efiEect thus realizable by the construction herein shown and described imparts to my pencil sharpener several novel advantages. divided graphite produced in the pencil sharpening operation are retained by and in the pencil sharpener in the simplest possible manner; second, the possibility of escape of Wood shavings and finely divided graphite during the pencil sharpening operation is eliminated; and, third, the compacted wood shavings are discharged in a more or less integral mass when the pencil sharpener is emptied.

While the preferred embodiment of my invention has been shown and described, my invention comprises all devices employing the same principles for the accomplishment of the same or similar results; and the appended claim is to be construed as broadly as possible in view of the prior art.

Having thus described my invention, WhatI claim is: r

In a pencil sharpener, the combination of a body provided with a longitudinally disposed pencil receiving chamber, blade means parallel to and intrusive into the pencil receiving chamber, and a snugly fitting cover sheathing the said body save at its rear end and bottom and pivoted upon the said body near the mouth of the pencil receiving chamber, the said cover forming with the said body a conico-cylindrical chamber the end of which nearer the mouth of the pencil receiving chamber is open and the area of whose vertical cross-section perpendicu- First, the wood shavings and finely.

lar to the length of the blade means is substantially proportional to the corresponding vertical cross section of the pencil receiving chamber throughout the length of the conical portion of the said chamber but of lesser proportionality throughout the cylindrical portion of the said chamber, and the said cover being rotatably displaceable from the top of the said body in a direction perpendicular to the plane of the top of the said body.

MORRIS L. ULLMAN. 

